Clock thermostat



June 26, 1951 c. G. KRONMILLER CLOCK THERMOSTAT 3 Sheets-Sheet 1 FiledJan. 14, 1948 June 25, 1951 c. G. KRONMILLER 2,558,617

CLOCK THERMOSTAT Filed Jan. 14. 1948 3 Sheets-Sheet 2 Gttorneg June 26,1951 c. G. KRONMILLERA 2,558,617

CLOCK THERMOSTAT Filed Jan. 14, 1948 3 Sheets-Sheet 3 :inventor Cam. G.Mmm/LLM Gttorneg Patented June 26, 1951 oLoox TmnMosTaT Mon-1 Gxmnmiuer, Edina, Mmm, mmm to Minneapolis-Honeywell Regulator Company,Minneapolis, Minn., a corporation of Delaware Application January 14,1948, Serial No. 2,230

. c ,1 s l The present invention is directed to' a control device whosecontrol point is adapted to be shifted by a clock mechanism. Moreparticularly the invention is directed toa clock thermostat that isadapted to maintain one' temperature during the day and a reducedtemperature'during the night or during periods of non-occupancy.

'An object of the invention is to provide a control device having aclock mechanism for shifting the control pointbetween two adjustablevalues.

Another object is to provide a time adjusted control device having meansextending outside the housing Vfor the device for setting the high andlow control points in a convenient manner.

A further object is to provide a clock thermostat in which the day andnight temperature settings are selected by a pair of levers having theirends extending beyond one end of the instrument case and cooperatingwith a temperature scale at the end'of the case.

A further object of the invention is to provide a clock driven camhaving an adjustable raised portion for shifting a member betweenadjustable abutments to vary the control point of a condition responsivedevice.

Another object is to provide an adjustable cam, the raised portion ofwhich may be adjusted to cover a maximum arc that is more than twice theminimum possible arc.

Another object is to provide a novel cam for shifting control pointbetween day and night settings that is rotatable with a twenty-four hourdial and has pointers adjustable with respect to the dial to determinethe times at which the control point will be shifted.

Other objects will be apparent from the following written descriptionand claims, and from the drawings, in which Figure l is a face view of aclock thermostat with certain parts broken away and with the mechanismin a position to control at a selected reduced temperature;

Figure 2 is a bottom view of the instrument shown in Figure 1 withcertain parts broken away and certain parts in section;

Figure 3 is a fragmentary view of the mechanism illustrated in Figures 1and 2 with the instrument base eliminated and with the parts in aposition to control at a selected elevated temperature; f

Figure 4 is a view of the composite cam adjusted to provide the maximumeffective raised proiile, and

Figure 5 is an exploded view of the twenty-four hour dial and camassembly.

is claims. (ci. zoo-136.3)

morning. Provision is also made for selecting the desred day and nighttemperatures. A feature of the ldescribed device is that the dayandnight temperature selecting levers extend outside the housing of thedevice and may be adjusted -to maintain a constant temperature when theocev sion arises. Referring now to the drawing, the clock ther-l mostathas a generally fiat and rectangular'base lli which is adapted formounting on a vertical wall surface of a room. The base Il is recessedon its underside to facilitate wiring thev device and also toaccommodate the temperature adjusting levers as will hereinafter appear.A cover or screen Il in the form of an inverted box with-its open sideresting against the base Il encloses the clock mechanism, thermostat,and adjusting mechanism. The top and bottom surfaces'ofl the screen Ilare provided with a plurality of openings I2 to permit room airtocirculate through the screen H and over the thermostatic element. 'I'heopenings I2 are also beneilcial'in conducting heat away from theclockmechanism which is preferably of the type operating onv regulatedfrequency alternating current. 'I'he screen I I is provided withsuitable projections that enter openings in the base i0 so that thecover may be fixed in place by tightening a pair of screws Il extending'through the upper and lower edges of the bsse.- An opening in the frontface oi' 'the screen Ii is covered with a clear plastic dial il whichcarries the clock numerals and through which the clock hands arevisible.

Since, for the purposes of the presentdisclosure, the clock mechanismmay be of any type either spring wound or electric, no details of themechanism have been shown and it is illustrated as being contained in aclock housing It suitably secured-to the base I0. Besides driving theclock hands the clock mechanism also drives a twentyfour hour dial Ilthrough a suitable gear train I! terminating in the -gear 2| which isrigidly aty tached to the dial I8 and rotatable therewith.

An adjustable cam assembly generally indicated at 2t is rotatable withthe dial il and together with the dial Il is rotatable on a pin 2l whichpending design application Ser. No. D. 138,361,

led April 14, 1947, now Patent Des. 151,905.

The base III is made of suitable insulating material such as moldedBakelite and carries brackets 3l and 3l which are electrically con-Anected to the binding screws 32 and 33. The

The bracket 36 carries an adjustable contact 35 and the bracket 3|carries an adjustable contact 36.l A bracket 36 mounted on the loweredge of the base is electrically connected to a terminal screw 33 andhas an upstanding portion 40 to which is attached a resilient blade 4I.A contact arm 42 is secured to the blade 4I adiacent the bracket 48 andextends upwardly'to carry a movable contact 43 that cooperates with thestationary contact 36. The blade 4I also extends upwardly to carry acontact 44 that cooperates with stationary contact 35. The blade 4I and.-arm 42 are formed so that the portion of the blade 4I between thebracket 46 and its connection to the arm 42 biases contact 43 intoengagement with the stationary contact 36. The upper extension of theblade 4I passes through an opening in the arm 42 and is biased lightlyinto engagement with the right hand edge thereof. Stationary contact 35is adjusted So that it will engage the contact 44 and press the blade 4Iback slightly with respect to the arm 42 before contact 43 can engagethe contact 36. f This ycontact structure. together with thethermostatic element to be described later, is the subject of myco-pending application, Ser. No. 681,442, led July 5, 1946, now PatentRe. 22,998.

As mentioned above, both sets of contacts are biased to closed positionby the resilient blade 4 I. The contacts may be separated by a U-'shapedbimetallic thermostatic element 46 that is adapted to engage an abutment41 on the upper extremity of the contact arm 42. The bimetal element 46is pivoted on a pin 48 extending upwardly from the bracket 38. Thetemperature at which the element 46 will separate the contacts dependson the position of the upper end of the right-hand leg of the element. Apivot pin 50 extends outwardly from the base iand has pivoted thereto amember I that is connected to the right hand leg of the bimetal 46 by alink 52. A member 54 is also pivoted on the post 56 and normally moveswith the member 5I. However, an eccentric 55 pivoted in the member 54and engaging the member 5i adjusts the relative angular position of thetwo members about the pivot pin 50 for calibrating the device. A pin 51carried bythe left-hand end of the member 54 extends through an opening58 in the base I0 and is adapted to engage portions of a day temperatureadjusting arm 66 and a night temperature adjustment; arm 6I 'which arepivoted in the base I0 on a bolt 63. A pair of friction washers 64 areinterposed between the arms 60 and 6l and between a spring washer 65 andthe head of the bolt 63. The washers 64 are provided with ears 66 thatengage a portion of the base I0 to prevent rotation thereof, The righthand extremity of the arms 66 and 6l extend through an opening in thebase and underneath a scale plate carried at the right-hand-end of thebase' I6. The indicia on the plate 19 are located so as to be visible'when the screen II is in place and provide for adjustment of. day andnight temperatures without removing the screen Ii. Screws 1I and 12 areadapted to lock the arms 60 and 6I to the plate 10 in preventunauthorized adjustment of ternperature settings if desired..

Without reference to the function of' the cam and camV follower to bedescribed below. it will be seen that the resilient blade 4I tends tomaintain the contacts in closed position and through the arm 42 and itsabutment 41 tends to move the bimetal element 46 in a clockwisedirection and places the link 52 in compression to move the member 5Iand member 54 in a clockwise direction so that the pin 51 is inengagement with vthe day temperature adjusting arm 60, as shown becontrollable by the day temperature adjusting arm 60, since it is onlyby engagement of the pin 51 on member 54 with this arm that the bimetalelement 46 will be able to expand to move the contacts to open positionagainst the action of the resilient blade 4 l A cam follower 15 is alsopivoted on the post 56 and it is provided with a roller 16 that engagesa Ycam 23. The cam follower 15 is provided with a lower extension 18that extends generally parallel to the member 54 and is adapted toengage a screw 19 carried by member 54.

A spring 8l extends between the portion 18 of the cam follower 15 and anextension 83 of the member 54 and serves to bias the cam follower to aposition where the extension 18 engages the `screw 19. The purpose ofthe abutment between the extension 18 and the last member 54 is to limitrelative rotation therebetween and to.

eliminate the biasing effect of the spring 8| on the member 54 when theroller 16 of the cam follower 15 is out of engagement with cam assembly23, thus permitting the resilient plate 4I to bias the member 54 intoengagement with the day temperature adjusting arm 56 as above described.The screw 19 is adjusted so that the roller 16 will not engage the lowportion of the cam assembly 23 when the day temperature setting arm- SI1is raised to the highest possible temperature setting. Adjustment of thescrew 19 should also be such that when the roller 16 of the cam follower15 is on the high part of the cam and the night temperature adjustingarm 6I is'at its lowest possible setting, there will be some clearancebetween the screw 19 and the extension 18 of the cam follower to assurethat the pin 51 is held in engagement with the arm 6I. Thus it will beseen that the diiierence in radii between the low and high portion ofthe cam should be suiiicient to move the cam follower 15 through anangle slightly greater than the possible angular movement of the member54 as determined by the maximum temperature setting of the arm and theminimum tempera- With this construction, no great accuracy of the camprofile is required. Consequently the cam disks can be made by simplestamping operations.

As mentioned above, the dial I8 and the cam assembly 23 are rotatable ona pin 25 carried by the extension 26 of the clock motor housing I6. Camassembly 23 comprises four similarly shaped disks 85, 86, 81 and 88, asshown in Figures 4 and 5. The lower disk 85 is fixed to a sleeve 80 thatis directly rotatable on the pin Il. v'lfhe sleeve vll is fluted as at'il. tecooperate with complementaryprojections 02 on a pointer C3 whichcooperates with thedial il to indicatethe time at which the thermostatwill be adjusted fromthe high temperature setting to the low temperaturesetting. The upper cam disk I8 has a sleeve 95 fixed thereto whichpivots on the sleeve Il attached to the disk Il. The sleeve hasprojections 56 thereon that cooperatewith complementary recesses 98formed in a sleeve 91 attached to a pointer D! which cooperates with thedial I8 to indicate the time at which the temperature setting will beshifted from Vthat established by the adjusting arm il to thatestablished by the adjusting arm 6l. The sleeve ll is threadedat itsupper end to cooperate with a nut Ill that may be tightened to draw thecam disk and the pointer toward the dial II to lock-the parts to thedial so that they will be rotated as a unit by the clock motor.v Aspring washer Il! is interposed between the disk 88 and the dialto-assist in so locking the parts together. The axially projectinglengths of the sleeves l and $1 as well as of theV projections 96 aresuch that suflicient axial movement is permitted to allow drawing thecam disk Il andthe pointer 9! tightly against the dial i8 as the nut itlis tightened on the sleeve Sii. Likewise the cooperation between theiluting-II in the sleeve st and the projection l! on the pointer 93 issuch that axial movement of the parts is permitted as the nut I istightened on the sleeve 96.

The cam disk 86 is provided with-a short lateral projection IM thatcooperates with an arcuate opening |05 in the disk l5 to limit pivotalmovement-between the two disks. With the projection l in one end of theslot |05 the contours of the two disks are. coincident while at theother-.end of the permitted movement the raised edges of the high partsof the cam cover an extended arc but no 'gap is permitted therebetween.The disk 86 is provided with an arcuate opening lli that cooperates witha projection lll on the disk 8l and likewise limits relative rotationbetween these two disks. Disk Il is also provided with a projection Illthat cooperates with a -radial opening Il! in the disk It for a similarPurpose. 'Ihe position of the lower disk Il relative to the upper diskIl and the position of the cam assembly relative to the dial Il may beadjusted by loosening the nut Ill, moving the pointers 93 and 9! toappropriate positions on the dial Il and retightening the nut lll.

As pointed out before, when the cam follower l5 is on the raised portionof the cam the thermostat will be adjusted to maintain the lower of thetwo temperature settings. When the pointers $3 and $9 are adjusted sothat the cam disks l5 and ll are in coincidence thenthe intermediatedisks 8i and Il will also be in coincidence therewith and the instrumentwill be adjusted to provide 'the minimum possible time of reducedtemperature. In: the illustrated construction it will amount toapproximately six hours. The maximum possible time of reducedtemperature adjustment is provided when the Acam disks are adjusted tothe position shown inFigure 4. It will be noted that the variousprojections and radial openings in the cam disk have caused the severaldisks. to be equally spaced and .to provide an effective raised vcamperiphery that is somewhat more than twice topcam disk andthe bottom camdisk tl will dtermine thelimlts 0f tht elective l'isd Dol'- tion of thelcam,but the relative positions of the intermediate cam disks `will bedefinitely fixed only at the' and maximumpcssible cam adjustments.

1 the cam 2l has been adjusted to lowerthe temperature setting to thatdetermined bythe arm 6| at eleven oclock. Since it is lnow approximatelya quarter to one `asindieated by the clock hands, the cam, which isrotating counterclockwise, has raised the roller 1I of the cam follower15 to raise the extension Il away from the abutment screw 19 and tensionthe spring Ilv to move the member 5I to a position determined by thetemperature setting arm il. It should be pointed out here that thespring 8l issomewhat stronger lthan the resilient blade li and moves thecontacts to open position through the bimetal element 45. However, whenthe room temperature is reduced sufficiently the bimetal element 4G willpermit the resilient blade 4| to reclose the .v

contacts.

Although the pointer 93 is not visible in Figure l it is evident fromthe position of the cam segments that they have been adjusted to provideapproximately eight hours of reduced temperature. Hence at about sevenoclock the roller 16 of the cam follower 15 will ride oif the highsurface of the cam and will be moved in a clockwise direction as theroller 16 moves down-the inclined surface of the upper cam disk. Ihe pinil on the member 54 will remain in engagement with the night temperaturesetting arm tl until the extension 'I8 of the cam follower engages theabutment screw l! on the lever 54. Further closkwise movement of the camfollower will permit the pin 5l to be moved from the arin 6l to the daytemperature adjusting arm it duef to the bias of the resilient blade 4I.The parts will then be in the position shown in Figure 3; If the roomtemperature is suciently low, after the v contacts have been moved toclosed position by the bias of the blade Il the bimetal element I8 maybe out of engagement with the abutment 4l of the contact arm I2 andtherefore will exert no clockwise force on the members Sl'fand M and thepin 51 may therefore be in engagement with neither of the arm ill nor6|. Contacts will remain closed then until the room temperature risessumciently to separate the legs ofthe U- shaped bimetal element 45causing the member i4 to raise the pin 5l into engagement with the daytemperature adjusting arm Gli. Engagement of the pin il and the arm 6henables the element 4i to exert a thrust to open the contacts.

On continued counterclockwise movement of the cam the roller 'I6 of thecam follower l5 will be engaged by the inclined surface of the lower camdisk to rotate the cam follower in a counterclockwise direction and thepin 5l on the member ilwill start to move toward the adjusting arm 6i assoon as the cam follower starts to move. After the pin il engages thearm 6I the cam followerextension 'I8 will leave the abutment screw 19,and the pin 51 will be maintained against arm GI by the tension of thespring 8l. In this position of the parts the bimetal element 45 actsagainst an abutment established by the member 54 and the spring 8l toovercome the resilient blade Il in order to open the contacts.

'While the arrangement for providingv an adjustablehi'gh and lowtemperature setting and the cam structure for shifting between these twosettings has been described in connection with a particular bimetalthermostat, it is obvious that other condition responsive means could besubstituted without departing from the spirit of the invention. Insteadof contacts operated by a thermostatic element it will be apparent thata control valve such as used in pneumatic thermostats might besubstituted. Likewise, a volatile fill bellows might be substituted forthe bimetallic element. Also, in the broader aspects of the invention,it is not essential that the device be used to control temperature, anda humidity responsive element might be substituted for a temperatureresponsive element where it is desired to maintain different humidityconditions at different times. p

The various features of novelty of the invention can be put intopractice in apparatus taking many different forms and it is to beunderstood. therefore, that the scope of the invention is to be limitedonly by the appended claims.

I claim as my invention:

1. In a control device, a base, condition responsive means having a rstportion shiftable with respect to said base, a pair of adjustable stopslimiting the range of possible shift of said condition responsive means,control means carried by said base and adapted to be actuated by asecond portion of said condition responsive means at a condition valuedepending on the position of the first portion of said conditionresponsive means with respect to said base, a spring acting between saidbase and the second portion of said condition responsive means forbiasing said condition responsive means to a position determined by oneof said stops, and means for shifting said condition responsive means toa position determined by the other of said stops against the 'bias ofsaid spring.

2. In a clock thermostat, a stationary contact,

a contact movable with respect to said stationary contact betweenengaged and disengaged positions, a spring biasing said movable contacttoone of its operative positions, a clock mechanism, a cam driven bysaid clock mechanism, a cam follower, a member movable between first andsecond positions, a bimetal element interconnecting said member and saidmovable contact and adapted to move said contact against the bias ofsaid spring, and a strain release conection between said cam followerand said member.

3. In a clock thermostat, a stationary contact, a contact movable withrespect to said stationary contactbetween engaged and disengagedpositions, a spring biasing said-movable contact to one of its operativepositions, a clock mechanism, a cam driven by said clock mechanism, acam follower, a pair of adjustable stops, a member movable between firstand second positions determined by said stops, a bimetal elementinterconnecting said member and said movable contact and adapted to movesaid contact against the bias of said spring, and a strain releaseconnection between said cam follower and said member.

4. In a clock thermostat, a stationary contact, a contact mo'. able withrespect to said stationary contact between engaged andy disengagedpositions, a spring biasing said movable contact to one of its operativepositions, a clock mechanism, a cam driven by said clock mechanism, acam follower, a pair of arms pivoted on the same axis and cooperatingwith a scale having temperature indicia thereon, a member movablebetween first and second positions determined by the positions of saidarms. a bimetal element interconnecting temperature sensitive switchcarried on said base,

a pair of adjusting arms, a member for adjusting the control point ofsaid temperature sensitive switch, a clock driven cam and a cam followerconnectedto said member for shifting said member between positionsdetermined by said arms, said cam comprising more than two similarlycontoured overlying sections each of which is provided with interlockingmeans cooperating with adjacent disks to prevent separation of theeffective raised edge thereof, said interlocking means also causingcoincidence of said sections at one extremity of adjustment thereof.

6. In a clock thermostat, temperature sensitive controlling means, meansfor shifting the control point of said controllingv means, a clockmotor, a dial rotated by saidmotor, indicia of time on one surface ofsaid dial, a composite cam comprising more than two of similarlycontoured disks each havingraised and reduced peripheral portionspivoted coaxially with said dial and lying on the side of said dialopposite said indicia, a. pointer on the indicia side of said dialrotatable with one of said disks, a pointer on the indicia side of saiddial rotatable with another of said disks, interlocking means actingbetween adjacent disks to prevent separation of the raised portions ofsaid disks, and a cam follower operatively connected to said shiftingmeans.

7. In a clock thermostat, temperature sensitive controlling means, meansfor shifting the control point of said controlling means, a clock motor,a dial rotated by said motor, indicia of time on one surface of saiddial, a composite cam comprising a plurality of similarly contoureddisks each having a raised and a reduced peripheral portion pivotedcoaxially with said dial and located on the side of said dial oppositesaid indicia, a first pointer on the indicia side of said dial rotatablewith the cam disk nearest said dial but slidable axially with respectthereto, a second pointer on the indicia side of said dial rotatablewith the cam disk farthest from said dial but slidable axially withrespect thereto, means for forcing said pointers and said cam disksagainst said dial to provide a unitary structure rotatable by said clockmotor, and a cam follower cooperating with the raised portions of saidcam disks operatively connected to said shifting means.

8. In a clock thermostat, temperature sensitive controlling means, meansfor shifting lthe control point of said controlling means, a clockmotor, a dial rotated by said motor, indicia of time on one surface ofsaid dial, a composite cam comprising a plurality of similarly contoureddisks each having a raised and a reduced peripheral portion pivotedcoaxially with said dial and located on the side of said dial oppositesaid indicia, a first pointer on the indicia side of said dial rotatablewith the cam disk nearest said dial but slidable axially with respectthereto, a second pointer on the yindicia side of said dial rotatablewith the cam disk farthest from said dial but slidable axially withrespect thereto, means for forcing said pointers and said cam disksagainst said dial to provide a unitary structure rotatable by said clockmotor, interlocking means acting between adjacent cam disks to prei entcircumferential separation of the raised portions thereof, and a camfollower cooperating with the raised portions of said cam disksoperatively connected to said shifting means;

9. An adjustable cam assembly comprising a rotatable dial, indicia oftime on one surface of said dial, a composite cam comprising a pluralityof similarly contoured disks each having a raised and a reducedperipheral portion pivoted coaxially with said dial and located on theside of said dial opposite said indicia. a first pointer on the indiciaside of said dial rotatable with the cam disk nearest said dial butslidable axially with respect thereto, a second pointer on the indiciaside of said dial rotatable with the cam disk farthest from said dialbut slidable axially with respect thereto, and means for forcing saidpointers and said cam disks against said dial to provide a unitaryrotatable structure.`

10. In a clock thermostat, temperature sensitive controlling means,means for shifting the control point of said controlling means, a clockmotor, a dial rotated by said motor, indicia of time on one surface ofsaid dial, a composite cam comprising a plurality of similarly contoureddisks each having a raised and a reduced peripheral portion pivotedcoaxially with said dial and located on the side of said dial oppositesaid indicia, a first pointer on the indicia side of said dial rotatablewith the cam disk nearest said dial but slidable axially with respectthereto, a second pointer on the indicia side of said dial rotatablewith the cam disk farthest from said dial but slidable axially withrespect thereto, means for forcing said pointers and said cam disksagainst said dial to provide a unitary structure rotatable by said clockmotor, interlocking means between said cam disks to preventcircumferential separation of the raised portions thereof, saidinterlocking means also causing alignment of all of said disks when saidpointers are adjusted to a predetermined position for providing aneffective composite cam surface having a minimum raised portion equal tothe raised portion of one of said disks, and a cam follower cooperatingwith the raised portions of said cam disks operatively connected to saidshifting means.

11. In a clock thermostat, a base, a thermostatic switch, a memberpivoted on said base and connected to said switch for adjusting thecontrol point of said switch, a pair of abutments for limiting pivotalmovement of said member, a cam follower pivoted on said base coaxiallywith said member, cooperating abutments on said cam-follower and saidmember, a spring biasing the abutment on said cam follower intoengagement with the abutment on said member and a clock driven cam forpositioning said cam follower.

y 12. In a clock thermostat, a base, a' thermostatic switch, a firstmember pivoted on said base for adjusting the control point of saidswitch, a second member pivoted on said base coaxially with said firstmember, means for adjusting the angular relation between said members, apair of abutments adjustable with respect to said base adapted to engagesaid second member for limiting pivotal movement of said second members,a cam follower pivoted coaxially with said members and having anabutment adapted to engage one of said members, a spring biasing saidcam follower to a position determined by the position of said members,and a clock driven cam for positioning said cam follower.

13. In a clock thermostat, temperature sensitive controlling means,means for shifting the control point of said controllingmeans, a clockmotor, a dial rotated by said motor. indicia of time on one surface ofsaid dial, first and second pointers cooperating with said indicia, rstand 'second cam disks on the opposite side of said dial, a memberextending through said dial and interconnecting said ilrst cam disk andsaid rst pointer, a member extending through said dial andinterconnecting said second cam disk and said second pointer, a thirdcam disk intermediate said first and second disks, said cam disks, saidpointers and said members being rotatably adjustable with respect tosaid dial about the pivotal axis of said dial, said cam disks beingsimilarly contoured and having extended and reduced arcuate peripheralportions, interlocking means between adjacent cam disks preventingseparation of the extended peripheral portions of said disks, saidinterlocking means also causing coincidence of all of said cam disks atone relatively adjusted position of said pointers, a cam followeradapted to engage the peripheries of said cam disks, and a linkagebetween said cam follower and said shifting means.

14. In a clock thermostat, temperature sensitive controlling means,means for shifting the control point of said controlling means, a clockmotor, a dial rotated by said motor, indicia of time on one surface ofsaid dial, first and second pointers cooperating with said indicia,first and second cam disks on the opposite side of said dial, a memberextending through said dial and interconnecting said first cam disk andsaid rst pointer, a member extending through said dial andinterconnecting said second cam disk and said second pointer, a thirdcam disk intermediate said first and second disks, said cam disks, saidpointers and said members being rotatably adjustable with respect tosaid dial about the pivotal axis of said dial, said cam disks beingsimilarly contoured and having extended and reduced arcuate peripheralportions, the raised portion of each cam disk including an angle of lessthan one hundred and twenty degrees, interlocking means between adjacentcam disks preventing separation of the extended peripheral portions ofsaid disks, said interlock--4 ing means also causing coincidence of allof said cam disks at one relatively adjusted position of said pointers,a cam follower adapted to engage the peripheries of said cam disks, anda linkage between said cam follower and said shifting means.

l5. In a clock thermostat, a base, a thermostatic switch, a pivot postmounted on said base. a first member pivoted on said post for adjustingthe control point of said switch, a second member pivoted on said post,means for adjusting the angular relation between said members, a pair ofabutments adjustable with respect to said base adapted to engage saidsecond member to limit pivotal movement of said second member fordetermining the control point of said switch, a cam follower pivoted onsaid post and having an abutment adapted to engage one of said members,a spring biasing said cam follower toward a position determined by theposition of one of said members, and a clock driven cam for positioningsaid cam follower.

16. In a clock thermostat, temperature sensitive controlling means,means for shifting the control point of said controling means, a clockmotor, a dial rotated by said motor, indicia of time on one surface ofsaid dial, first and second pointers cooperating with said indicia,first and second cam disks on the opposite side of said dial, a memberinterconnecting said rst cam disk and said nrst pointer, a memberinterconnecting said second cam disk and said second pointer, a thirdcam disk intermediate said first and second disks, said cam disks, saidpointers and said members being rotatably adjustable with respect tosaid dial about the pivotal axis of said dial, said cam disks beingsimilarly contoured and having extended and reduced arcuate peripheralportions, interlocking means between adjacent cam disks preventingseparation of the extended peripheral portions of .said disks, saidinterlocking means also causing coincidence oi' all of said cam disks atone relatively adjusted position of said pointers, a cam followeradapted to engage the peripheries of said cam disks, and a-vlinkagebetween said cam Vfollower and said shifting means.

.17.A In a clock thermostat, temperature sensi= tive controlling means,means for shifting the control point of said controlling means,.a clockmotor, a dial rotated by said motor, `indicia of time on said dial, rstand second pointers cooperating with said indicia, first and second camdisks, a member interconnecting said first cam disk and said irstpointer, a -member interconnecting said second cam disk and said secondpointer, a third cam disk intermediate said first and second disks, saidcam disks, said pointers and said members being rotatably adjustablewith respect to said dial about the pivotal axis of said dial, said camdisks having arcuate extended-peripheral portions of substantially iden-,ticalV configuration, interlocking means between adjacent cam diskspreventing separation of the i2 extended peripheral portions of saiddisks, said interlocking means also causing coincidence of the extendedportions of all of said cam disks, at one relatively adjusted positionof said pointers, a cam follower adapted to engage the peripheries ofsaid cam disks, and a linkage between said cam follower and saidshifting means.

18. An adjustable cam assembly comprising a rotatable dial havingindicia thereon, a composite cam comprising a stack of disks pivotedcoaxially with said dial, a rst .pointer cooperating with said indiciaand rotatable with a first one oi said disks, a second pointercooperating with said in relatively adjusted position of said pointers.

CARL G. KRONMILLER.

REFERENCES eraan The following references are ofrecord in the le of thispatent:

UNITED STATES PATENTS Number Name Date 2,231,686 Shaw' Feb. 11, ,19412,296,063 Shaw Sept. 15, i942 2,368,005 Crise Jan. 23, 1945

